Of the many semi-truck accidents that take place across the country, arguably none are more devastating than an underride truck crash, where another vehicle collides with the rear or side of a big rig and is shoved underneath the truck. In an underride truck accident, the injuries are often fatal and the wreckage incredibly disturbing.

Now, the Insurance Institute for Highway Safety (IIHS), which has long championed for improved underride safety, has released crash test data demonstrating that side guards could be an important next step in improving the safety of motorists and truck drivers on America’s roads. A resistant trucking industry, however, still stands in their way.

IIHS Study Shows Side Underride Truck Guards to Be Effective

Since 2011, the IIHS has conducted crash tests involving rear underride guards, which are required by law, but this spring the IIHS conducted their first crash tests to analyze side underride guards, which are not required by law in the U.S., but commonly cited by safety advocates as an important element of truck safety.

The side underride truck crash tests involved two 53-foot-long dry van trailers, both of which were struck by a midsize car traveling at 35 mph. The difference was that one of the trucks was outfitted with a side underride device and the other with a skirt that would improve aerodynamics and fuel efficiency, but had no safety focus.

When the test car collided with the truck that had a side underride protection device (the AngelWing made by Airflow Deflector Inc.) the front of the car was crushed and the AngelWing bent, but the car was stopped from moving under the truck. The airbag deployed and the seat belt properly held the dummy in the passenger car.

In sharp contrast, when the test car hit the semi-truck that had only a skirt for aerodynamics, it hit the side of the trailer and continued traveling forward, becoming wedged underneath the truck. Part of the roof was sheared from the car, demonstrating why air bags and seatbelts may not function correctly in an underride truck crash and why decapitations are common. According to the IIHS, anyone traveling inside that car would likely have died.

In an Underride Truck Crash, Side Impact is More Common Than Rear

It’s hard to understate the importance the latest IIHS findings may have in improving truck safety, as side underride truck crashes are surprisingly common.

In 2015, according to IIHS data, there were 301 passenger vehicle occupant deaths in 2-vehicle crashes with tractor trailers where the passenger vehicle had hit the side of big rig. According to the same data, there were 292 deaths where the passenger vehicle had hit the rear of the truck. The year prior, the figure for side impact deaths was even higher, with 308 deaths.

The IIHS has known side underride guards could be beneficial for years. A 2012 study from the organization found that side underride protection could reduce injury risk in approximately three-fourths of large truck side crashes producing a fatality of serious injury to a passenger vehicle occupant. The figures got even better when looking only at crashes with semitrailers: An almost 90 percent reduction.

David Zuby is the Insurance Institute’s executive vice president and chief research officer, and he feels that the crash test results demonstrate the next step that needs to be taken in truck safety.

“Our tests and research show that side underride guards have the potential to save lives,” Zuby said. “We think a mandate for side underride guards on large trucks has merit, especially as crash deaths continue to rise on our roads.”

Family Members Petition on Behalf of Underride Truck Crash Victims

There are perhaps no fiercer advocates for underride truck crash safety improvements than the family members who have lost loved ones in such crashes, and many of these individuals have taken it upon themselves to lobby Washington for stricter regulations that would prevent other families from experiencing what they’ve gone through.

Marianne Karth Calls for Change After Losing Two Daughters in Semi-Truck Crash

While driving in Georgia, Marianne Karth was hit by a semi-truck and pushed under the rear of another semi-truck. Karth survived the accident, but two of her daughters did not, partially, according to investigators, because the underride guard had failed on the big rig.

Since then Karth has continued to work tirelessly for better standards when it comes to underride guards.

“I am convinced stronger rear underride and mandatory side underride guards will save lives, that’s what gives me the strength to continue,” Karth said in an interview with Trucks.com. “I will not compromise on this issue because too many people have died already and we can’t compromise any longer.”

Lois Durso Believes Truck Side Guards Could Have Saved Her Daughter

Lois Durso also lost her daughter to an underride truck crash. Twenty-six-year-old Roya Sadigh was driving with her fiancé in snowy whether when they lost control of their vehicle and hit the side of a semi-truck, where the vehicle was stuck before being run over by the rear tires of the truck.

Upon researching side underride guards, Durso realized that her daughter might have survived the crash if such protection had been in place.

“I was very angry—with the trucking manufacturers and also the federal government,” Durso has said. “They’re fully aware people are dying as a result of their trailer design. And yet they do nothing about it.”

Together with Karth, Durso drafted the Roya, AnnaLeah and Mary Comprehensive Underride Protection Act of 2017.

Jennifer Tierney Fights for Her Father After Fatal Truck Crash

Like Karth and Durso, Jennifer Tierney lost a loved one to an underride truck crash. In her case, it was her father, who hit a semi-truck that was backing into a field across a highway in the dark. Her father, who Tierney says, “had no opportunity to brake,” hit the side of the truck and his vehicle became wedged underneath it, eventually emerging on the other side as wreckage.

In the time since her father’s passing, Tierney has focused on side underride safety and was able to convince the federal government to require reflective tape on the sides of trucks. She’s thrilled that the IIHS has begun testing side guards.

“I’m absolutely delighted beyond belief that these underride crash tests have happened,” Tierney said in an interview with Fox23 News. “It’s been a long difficult battle to get something done. These crashes are catastrophic.”

U.S. Lagging Behind Other Countries’ Underride Regulations

America’s underride safety regulations are less strict than its neighbor to the north, where rear underride guards must be able to withstand about twice as much force as rear guards are required to withstand here in the U.S.

Europe has even stricter requirements that call for not only rear underride guards, but side underride guards, like those recently tested by the IIHS. They’ve had the side and rear underride truck crash safety rules in place since 1989, and it was there that Durso realized how much safer such protective equipment can make truck crashes.

Trucking Industry Says Side Guards Aren’t the Solution

Despite safety advocates singing the praises of side underride protection devices, the trucking industry is not convinced. They feel instead that the safety devices come with more risk (such as added weight and stiffer, more crack-prone frames), and fail to address the real issue.

Sean McNally is the spokesman for the American Trucking Associations (ATA) and says the organization would rather focus on accident prevention than improved safety during a crash.

“It’s important to recognize that all crashes are tragedies, but we also need to recognize that these guards are collision mitigation—and not collision avoidance—equipment and ATA’s primary safety goal is to prevent crashes,” McNally said.

According to McNally, the ATA will instead focus their support on technology, like automatic emergency braking and forward collision warning systems. As truck safety advocates would be quick to point out, however, both of those technologies could easily be rendered useless in an underride truck crash.